Methods and apparatus for controlling the speed of a vehicle and its distance to objects present in the path of its movement are known. Not only may the speed of a vehicle be controlled automatically by means thereof, but also a safety distance may be set between the vehicle and another vehicle ahead of it, especially for travelling in a convoy. It has been found, however, that the known methods and apparatus are not sufficiently adaptable to respond appropriately to all travel conditions. For instance, a driver may want to accelerate his vehicle while still in its current driving lane when preparing for passing another vehicle, even if this results in reducing the safety distance between his own and the vehicle to be passed. Such action is not possible with known systems.